The present invention relates to a method of monitoring oxygen concentration in a production process of tea beverages or alcoholic beverages including beer and an apparatus for executing the same.
The oxidation of tea beverages such as tea and green tea and alcoholic beverages such as beer and sparkling liquor progresses with the passage of time after their production, so that their flavor gradually deteriorates. This is mainly due to oxygen entering these beverages in the process of their production. In the case of beer, for instance, if only an extremely small amount of oxygen enters the beer during its production process, the oxygen molecules are partially reduced by electrons transferred from metal (Fe, Cu) ions existing in the beer in its preserved state so that active oxygen is produced. The active oxygen oxidizes a variety of ingredients in the beer, such as isohumulone and alcohols, and generates aldehydes, which is the cause of aging odor, thereby deteriorating the flavor.
A variety of methods of reducing entry of oxygen in the production process of beverages as much as possible have been studied as one of measures to prevent the oxidation of beverages. In order to achieve this, it is necessary to constantly know the concentration of oxygen in the production process, so that various studies have been conducted of effective timing and method of knowing.
It is an object of the present invention to provide a monitoring method and apparatus for constantly monitoring the concentration of oxygen in real time throughout the production process of beverages. By measuring and monitoring the amount of oxygen dissolved in a beverage immediately before filling and the oxygen concentration of the vapor phase in a storage tank storing the beverage immediately before filling, an overall estimation of the effect of oxygen is made based on both of the concentrations of oxygen.
The inventors of the present invention have focused on the amount of oxygen dissolved in the beverage before filling in the production process and the concentration of oxygen included, immediately before filling, in the vapor phase formed in the storage tank storing the beverage.
The storage tank is internally occupied by the beverage to be filled and the vapor phase of the space part, and the amount of oxygen dissolved in the beverage is affected by the concentration of oxygen in the vapor phase.
That is, in this case, equilibrium is established between the liquid phase taken up by the beverage and the vapor phase of the space part. Therefore, if there is a difference in the concentration of oxygen between the phases, oxygen moves from the phase of high density to the phase of low density to cancel the difference in concentration, so that the concentrations converge into a state of equilibrium. Accordingly, if the concentration of oxygen in the vapor phase of the storage tank is higher than the concentration of oxygen in the beverage, oxygen moves from the vapor phase into the beverage so that the amount of dissolved oxygen is increased.
Normally, replacement is performed in the space part with gas that does not affect the flavor of the beverage, such as carbon dioxide or nitrogen gas. Accordingly, the quality of the gas to be supplied greatly affects the concentration of oxygen in the space part. Entry of oxygen may occur if the gas supply system has a defect or a failure.
Further, in the case of filling a container with the beverage, the container is filled with carbon dioxide or nitrogen gas, and the beverage is filled into the container with the filling gas being discharged. Generally, the discharged filling gas is supplied into the storage tank at this point. In this case, if replacement with the filling gas is not fully performed inside the container due to the malfunction of a filling device, the filling gas having a large amount of oxygen remaining therein is delivered into the storage tank.
Further, even if the concentration of oxygen in the space part inside the storage tank is low, entry of oxygen into the beverage occurring previously at the time of producing the beverage itself may be revealed in the form of an increase in the concentration of oxygen dissolved in the beverage.
Thus, according to the present invention, the concentration of oxygen in the vapor phase part inside the storage tank and the concentration of oxygen dissolved in the beverage inside the storage tank are measured, and the effect of oxygen on the beverage is determined from both concentrations of oxygen.
Further, according to the present invention, the concentration of oxygen in the vapor part in the storage tank and the concentration of oxygen included in the beverage flowing through a supply channel supplying the beverage to the storage tank are measured and monitored, and the effect of oxygen on the beverage is determined from both concentrations of oxygen. Thereby, the concentration of oxygen dissolved into the beverage in the process of producing the beverage itself, which process is upstream from the filling process, and the concentration of oxygen in the space part of the storage tank can be monitored respectively, so that the process responsible for the entry of oxygen can be specified.
Further, as a system for constantly measuring and monitoring the concentration of oxygen in the vapor phase of the space part inside the storage tank in real time, an oxygen sensor may be attached directly to the storage tank to measure the concentration of oxygen in the space part inside the tank, and the measured data (electrical signal) may be displayed on a determination apparatus or a display unit that is separately provided externally. Alternatively, gas in the space part inside the storage tank may be discharged outside, and the concentration of oxygen in the discharged gas may be measured by a measuring device to be determined and displayed. As an oxygen concentration meter employed in this case, a measuring apparatus using a galvanic cell type oxygen sensor, a zirconia type oxygen sensor, or a thermoparamagnetic oxygen sensor may be employed.
Further, as a device for measuring the concentration of oxygen dissolved in the beverage, the above-described oxygen concentration measuring apparatus using a sensor using a galvanic cell type oxygen sensor or a zirconia type oxygen sensor is employed, and the sensor is attached to the storage tank or the pipe channel supplying the beverage to the storage tank.
If it is confirmed, as a result of measuring the concentration of oxygen, that the concentration of oxygen exceeds a given allowable value, the beverage filling operation is stopped based on the measurement information from the measuring apparatus, and a warning is issued. Alternatively, if the measurement reveals that the excess of the concentration of oxygen over the given value is caused, for instance, by the concentration of oxygen in the space part inside the storage tank, the primary cause of the increase in the concentration of oxygen can be improved by increasing the supply of carbon dioxide or nitrogen gas to the storage tank.
A mode of the present invention is a method of monitoring a concentration of oxygen in a beverage production process, the method characterized by including: a step of continuously sampling gas in a space part inside a beverage storage tank storing a beverage to be filled, the beverage storage tank being provided to a beverage filler; a step of measuring a concentration of oxygen in the sampled gas; a step of comparing the measured value and a preset first reference concentration; a first determination step of issuing an alarm signal when the measured concentration of oxygen exceeds the first reference value;
a step of continuously measuring a concentration of oxygen included in the beverage inside the beverage storage tank; a second comparison step of comparing the measured concentration of oxygen in the beverage with a preset second reference value; and a second determination step of issuing an alarm signal when the measured concentration of oxygen in the beverage exceeds the second reference value.
Another mode of the present invention is a method of monitoring a concentration of oxygen in a beverage production process, the method characterized by including: a step of continuously sampling gas in a space part inside a beverage storage tank storing a beverage to be filled, the beverage storage tank being provided to a beverage filler; a step of measuring a concentration of oxygen in the sampled gas; a step of comparing the measured value and a preset first reference concentration; a first determination step of issuing an alarm signal when the measured concentration of oxygen exceeds the first reference value;
a step of continuously measuring a concentration of oxygen included in the beverage flowing through a beverage supply channel supplying the beverage to the beverage storage tank storing the beverage to be filled, the beverage storage tank being provided to the beverage filler; a second comparison step of comparing the measured concentration of oxygen in the beverage with a preset second reference value; and a second determination step of issuing an alarm signal when the measured concentration of oxygen in the beverage exceeds the second reference value.
Yet another mode of the present invention is an apparatus for monitoring a concentration of oxygen in a beverage production process, the apparatus characterized by including: sampling means for continuously sampling gas in a space part inside a beverage storage tank storing a beverage to be filled, the beverage storage tank being provided to a beverage filler; measuring means for measuring a concentration of oxygen in the sampled gas; comparison means for comparing the measured value and a preset first reference concentration; first determination means for issuing an alarm signal when the measured concentration of oxygen exceeds the first reference value;
measuring means for continuously measuring a concentration of oxygen included in the beverage inside the beverage storage tank; comparison means for comparing the measured concentration of oxygen in the beverage with a preset second reference value; and second determination means for issuing an alarm signal when the measured concentration of oxygen in the beverage exceeds the second reference value.
Yet another mode of the present invention is an apparatus for monitoring a concentration of oxygen in a beverage production process, the apparatus characterized by including: sampling means for continuously sampling gas in a space part inside a beverage storage tank storing a beverage to be filled, the beverage storage tank being provided to a beverage filler; measuring means for measuring a concentration of oxygen in the sampled gas; first comparison means for comparing the measured value and a preset first reference concentration; first determination means for issuing an alarm signal when the measured concentration of oxygen exceeds the first reference value;
measuring means for continuously measuring a concentration of oxygen included in the beverage flowing through a beverage supply channel supplying the beverage to the beverage storage tank storing the beverage to be filled, the beverage storage tank being provided to the beverage filler; second comparison means for comparing the measured concentration of oxygen in the beverage with a preset second reference value; and second determination means for issuing an alarm signal when the measured concentration of oxygen in the beverage exceeds the second reference value.
Yet another mode of the present invention is an apparatus for monitoring a concentration of oxygen in a beverage production process, the apparatus characterized by including: a flow channel for gas in a space part inside a beverage storage tank for storing a beverage to be filled to flow through to outside the beverage storage tank, the beverage storage tank being provided to a rotary beverage filler;
a distributor for receiving the gas from the flow channel and delivering the gas outside the beverage filler, the distributor being provided to a rotating central shaft part of the beverage storage tank; an oxygen measuring device constantly measuring a concentration of oxygen in the gas delivered from said distributor; a delivery device for delivering the gas inside the space part to the oxygen concentration measuring device via the flow channel and the distributor; and a determination device comparing the concentration of oxygen from the oxygen concentration measuring device with a preset reference value and issuing an alarm signal when the measured value exceeds the reference value.
In the above-described modes of the present invention, the concentration of oxygen in the vapor phase of the space part inside the beverage storage tank and the concentration of oxygen included in the beverage in the beverage storage tank are constantly monitored, and an alarm signal is issued when the concentrations of oxygen exceed the given reference values. Thereby, the quality of the beverage to be filled can constantly be increased.
Further, in measuring and monitoring the concentration of oxygen in the vapor phase of the space part inside the beverage storage tank, the gas can be sampled continuously from the space part so that the alarm signal may be issued when the given reference value is exceeded.